From deb916df447212c95cc90c60781c5cb3f1588173 Mon Sep 17 00:00:00 2001
From: Francois <thiebolt@irit.fr>
Date: Sun, 13 Mar 2022 20:48:44 +0100
Subject: [PATCH] SCD4x sensor is on way ...
---
.../libraries/neocampus_drivers/SCD4x.cpp | 378 ++++++++++--------
neosensor/libraries/neocampus_drivers/SCD4x.h | 31 +-
neosensor/libraries/neocampus_drivers/SHT2x.h | 2 +
.../libraries/neocampus_drivers/SHT3x.cpp | 2 +-
neosensor/libraries/neocampus_drivers/SHT3x.h | 2 +
neosensor/neosensor.ino | 7 +-
6 files changed, 243 insertions(+), 179 deletions(-)
diff --git a/neosensor/libraries/neocampus_drivers/SCD4x.cpp b/neosensor/libraries/neocampus_drivers/SCD4x.cpp
index 8d4a050a..0fab7df9 100644
--- a/neosensor/libraries/neocampus_drivers/SCD4x.cpp
+++ b/neosensor/libraries/neocampus_drivers/SCD4x.cpp
@@ -47,12 +47,18 @@ const char *SCD4x::units_co2 = "ppm";
const char *SCD4x::units_temp = "celsius";
const char *SCD4x::units_rh = "%r.H.";
-/* [static] initialize static vars */
-unsigned long SCD4x::_lastMsRead = 0;
-uint16_t SCD4x::_co2_sensor = (uint16_t)(-1);
-uint16_t SCD4x::_t_sensor = (uint16_t)(-1);
-uint16_t SCD4x::_rh_sensor = (uint16_t)(-1);
+/* [static] initialize static vars
+ * REMEMBER: only possible because there's ONLY ONE SCD4x per neOSensor
+ */
+unsigned long SCD4x::_lastCheck = 0;
+unsigned long SCD4x::_lastData = 0;
boolean SCD4x::_periodic_measure = false;
+uint16_t SCD4x::_co2_sensor = (uint16_t)(-1);
+boolean SCD4x::_co2_sensor_valid = false;
+uint16_t SCD4x::_t_sensor = (uint16_t)(-1);
+boolean SCD4x::_t_sensor_valid = false;
+uint16_t SCD4x::_rh_sensor = (uint16_t)(-1);
+boolean SCD4x::_rh_sensor_valid = false;
/**************************************************************************/
@@ -125,56 +131,40 @@ boolean SCD4x::begin( uint8_t addr=-1) {
if( (addr < (uint8_t)(I2C_ADDR_START)) or (addr > (uint8_t)(I2C_ADDR_STOP)) ) return false;
_i2caddr = addr;
-
-WARNING: if periodic measurement is already started ==> no others command will be accepted
-
-
// check device identity
if( !_check_identity(_i2caddr) ) return false;
/* set config:
* - software reset
* - calibration ?
- * - start periodic measurement
+ * - start periodic measurement ?
*/
// soft reset
+ // REMEMBER: we're shared across multiple modules !!
sw_reset( _i2caddr );
- // start periodic measurement
-TO BE CONTINUED
-
- /* start lastmsg time measurement.
- * This way, we get sure to have at least a first acquisition! */
- _lastMsRead = ULONG_MAX/2;
-
return true;
}
/*
- * Power ON
- * Note: starting
+ * Power modes: ON & OFF
*/
void SCD4x::powerON( void )
{
- // check if device's periodic measurement is not already engaged
- if( _periodic_measure ) return;
-
- // select proper command
- uint16_t _cmd = static_cast<uint16_t>(scd4xCmd_t::start_periodic_measurement);
- _i2caddr
-
- _periodic_measure = true;
}
-/*
- * Power OFF
- *
- */
void SCD4x::powerOFF( void )
{
- // device does not feature continuous integration so nothing to start or stop
+ // stop periodic measure
+ if( _periodic_measure ) {
+ uint16_t _cmd = static_cast<uint16_t>(scd4xCmd_t::stop_periodic_measurement);
+ _writeCmd( _i2caddr, _cmd );
+ delay(500);
+
+ _periodic_measure = false;
+ }
}
@@ -184,8 +174,28 @@ void SCD4x::powerOFF( void )
*/
/**************************************************************************/
-boolean SHT3x::acquire( float *pval )
+boolean SCD4x::acquire( float *pval )
{
+ // periodic measurement ?
+ if( !_periodic_measure ) {
+ // send command to acquire new sensors values
+ uint16_t _cmd = static_cast<uint16_t>(scd4xCmd_t::start_periodic_measurement);
+ _writeCmd( _i2caddr, _cmd );
+
+ _periodic_measure = true;
+ _lastCheck = millis();
+ _lastData = _lastCheck;
+ return false; // data won't get ready before min. 5000ms
+ }
+
+ // is measurement over ?
+ if( _isDataReady() ) {
+ /* extract new data along with CRC check
+ * and set proper flag in received data
+ */
+ _readSensor();
+ }
+
if( pval==nullptr ) return false;
// CO2
@@ -203,45 +213,24 @@ boolean SHT3x::acquire( float *pval )
return getRH( pval );
}
- log_warning(F("\n[SCD4x] unknown MeasureType 0x"));log_warning(_measureType,HEX);log_flush();
+ log_warning(F("\n[SCD4x] unknown MeasureType 0x"));log_warning(static_cast<uint8_t>(_measureType),HEX);log_flush();
return false;
}
-TO BE CONTINUED
-
-
-
/*
- * READ sensor's HUMIDITY
+ * READ sensor's CO2
+ * Note: only sends back new values
*/
-boolean SHT3x::getRH( float *pval ) {
-
+boolean SCD4x::getCO2( float *pval )
+{
if( pval==nullptr ) return false;
+ if( !_co2_sensor_valid ) return false;
- bool res = false;
- uint8_t retry = 3;
- uint16_t val;
-
- while( res==false and retry-- ) {
- res = _readSensor( &val );
- if( res == true ) break;
- delay(1); // 1ms demay between commands
- }
+ *pval = (float)_co2_sensor;
- if( res==false ) {
- // error ...
- log_error(F("\n[SHT3x] unable to read value ?!?!"));log_flush();
- return false;
- }
+ _co2_sensor_valid = false;
- uint32_t _tmp = (uint32_t)val;
- // from Adafruit SHT31
- // simplified (65536 instead of 65535) integer version of:
- // humidity = (shum * 100.0f) / 65535.0f;
- // 100.0 x _rh = val x 100 x 100 / ( 4096 x 16 )
- _tmp = (625 * _tmp) >> 12;
- *pval = (float)_tmp / 100.0f;
return true;
}
@@ -249,33 +238,41 @@ boolean SHT3x::getRH( float *pval ) {
/*
* READ sensor's TEMPERATURE
*/
-boolean SHT3x::getTemp( float *pval )
+boolean SCD4x::getTemp( float *pval )
{
if( pval==nullptr ) return false;
+ if( !_t_sensor_valid ) return false;
- bool res = false;
- uint8_t retry = 3;
- uint16_t val;
-
- while( res==false and retry-- ) {
- res = _readSensor( &val );
- if( res == true ) break;
- delay(1); // 1ms demay between commands
- }
-
- if( res==false ) {
- // error ...
- log_error(F("\n[SHT3x] unable to read value ?!?!"));log_flush();
- return false;
- }
-
- int32_t _tmp = (int32_t)val;
+ int32_t _tmp = (int32_t)_t_sensor;
// from Adafruit SHT31
- // simplified (65536 instead of 65535) integer version of:
- // temp = (stemp * 175.0f) / 65535.0f - 45.0f;
+ // temp = (stemp * 175.0f) / 65536.0f - 45.0f;
// 100.0 x _tmp = (17500 x _tmp) / (16384 x 4) - 4500
_tmp = ((4375 * _tmp) >> 14) - 4500;
*pval = (float)_tmp / 100.0f;
+
+ _t_sensor_valid = false;
+
+ return true;
+}
+
+
+/*
+ * READ sensor's HUMIDITY
+ */
+boolean SCD4x::getRH( float *pval ) {
+
+ if( pval==nullptr ) return false;
+ if( !_rh_sensor_valid ) return false;
+
+ uint32_t _tmp = (uint32_t)_rh_sensor;
+ // from Adafruit SHT31
+ // humidity = (shum * 100.0f) / 65536.0f;
+ // 100.0 x _rh = val x 100 x 100 / ( 4096 x 16 )
+ _tmp = (625 * _tmp) >> 12;
+ *pval = (float)_tmp / 100.0f;
+
+ _rh_sensor = false;
+
return true;
}
@@ -291,91 +288,81 @@ void SCD4x::sw_reset( uint8_t adr ) {
log_debug(F("\n[SCD4x] SOFT RESET action started ..."));log_flush();
_writeCmd( adr, static_cast<uint16_t>(scd4xCmd_t::reinit) );
delay( 20 );
+
+ _periodic_measure = false;
}
/*
* Read 16bits sensors values and check CRCs
* Note: SCD4x sensors read CO2, T and RH, all feature CRC
- * hence we store static values with a timestamp to avoid
- * multiple (useless) access for same things.
+ * Once a new data is available, we store it within the proper
+ * variable and we set its companion flag accordingly
*/
-bool SCD4x::_readSensor( uint16_t *pval ) {
-
- // do we need to acquire fresh sensors values ?
- if( (millis() - _lastMsRead ) >= (unsigned long)(SCD4X_SENSOR_CACHE_MS) ) {
-
- // select proper command
- uint16_t _cmd = static_cast<uint16_t>(scd4xCmd_t::read_measurement);
-
-TO BE CONTINUED
-
- uint8_t _retry = 3;
- bool status = false;
- while( status == false and _retry-- ) {
- // start acquisition command
- _writeCmd( _i2caddr, _cmd );
-
- // wait for integration
- delay( _integrationTime );
-
- // retrieve data:
- // MSB[T] + LSB[T] + CRC[T] + MSB[RH] + LSB[RH] + CRC[RH]
- uint8_t buf[6];
- if( readList_ll(_i2caddr, buf, sizeof(buf)) < sizeof(buf) ) {
- log_error(F("\n[SHT2x] insufficient bytes answered"));log_flush();
- yield();
- sw_reset( _i2caddr );
- continue;
- }
-
- // check first CRC ( TEMP )
- if( not crc_check(buf,2,buf[2]) ) {
- log_error(F("\n[SHT3x] invalid CRC for TEMP ...")); log_flush();
- yield();
- continue;
- }
-
- // check second CRC ( RH )
- if( not crc_check(&buf[3],2,buf[5]) ) {
- log_error(F("\n[SHT3x] invalid CRC for RH ...")); log_flush();
- yield();
- continue;
- }
-
- // both CRC are valid, let's grab the data
- _t_sensor = buf[0] << 8;
- _t_sensor |= buf[1];
- _rh_sensor = buf[3] << 8;
- _rh_sensor |= buf[4];
-
- status = true; // success
+bool SCD4x::_readSensor( void ) {
+
+ uint8_t _retry = 3;
+ bool status = false;
+
+ while( not status and _retry-- ) {
+ // cmd for read out serial number
+ _writeCmd( _i2caddr, static_cast<uint16_t>(scd4xCmd_t::read_measurement) );
+
+ // read answer 3 * (MSB + LSB + CRC)
+ uint8_t buf[9];
+ if( readList_ll( _i2caddr, buf, sizeof(buf)) < sizeof(buf) ) {
+ log_error(F("\n[SCD4x] not enough bytes read !"));log_flush();
+ delay(10); // 1ms min. delay between commands
+ continue; // ... and let's retry ...
}
- // check acquisition is ok
- if( not status ) {
- log_error(F("\n[SHT3x] unable to read sensor ...give up :("));log_flush();
- return false;
+
+ // we don't know about bytes validity but we've been able to read
+ // measurement from sensor :)
+ _lastData = millis();
+ status = true;
+
+ // DEBUG
+ hex_dump( (char*)buf, sizeof(buf) );
+ break;
+
+ // CO2 + CRC
+ if( crc_check(buf, 2, buf[2]) ) {
+ // CO2 retrieval
+ _co2_sensor = makeWord(buf[0], buf[1]);
+ _co2_sensor_valid = true;
+ }
+ else {
+ log_error(F("\n[SCD4x] CO2 CRC check failed !"));log_flush();
+ status = false;
}
- // success ==> update last read
- _lastMsRead = millis();
- }
- else {
- log_debug(F("\n[SHT3x] using cached value for "));
- if( _measureType == sht3xMeasureType_t::temperature ) {
- log_debug(F("TEMP sensor!"));
+ // T + CRC
+ if( crc_check(buf+3, 2, buf[5]) ) {
+ // T retrieval
+ _t_sensor = makeWord(buf[3], buf[4]);
+ _t_sensor_valid = true;
}
else {
- log_debug(F("RH sensor!"));
+ log_error(F("\n[SCD4x] Temp CRC check failed !"));log_flush();
+ status = false;
+ }
+
+ // RH + CRC
+ if( crc_check(buf+6, 2, buf[8]) ) {
+ // RH retrieval
+ _rh_sensor = makeWord(buf[6], buf[7]);
+ _rh_sensor_valid = true;
+ }
+ else {
+ log_error(F("\n[SCD4x] R.H CRC check failed !"));log_flush();
+ status = false;
}
- log_flush();
- }
- // send back pointer to proper value
- if( _measureType == sht3xMeasureType_t::temperature ) *pval = _t_sensor;
- else *pval = _rh_sensor;
+ // this is the end ... The Doors
+ break;
+ }
- return true;
+ return status;
}
@@ -438,7 +425,7 @@ bool SCD4x::crc_check( uint8_t data[], uint8_t nb_bytes, uint8_t checksum ) {
/*
- * Check that device identity is what we expect!
+ * Write i2c command
*/
void SCD4x::_writeCmd( uint8_t a, uint16_t cmd ) {
write8( a, (uint8_t)(cmd>>8) , (uint8_t)(cmd&0xFF) );
@@ -446,6 +433,55 @@ void SCD4x::_writeCmd( uint8_t a, uint16_t cmd ) {
}
+/*
+ * Check if read_measurement is over or not
+ * Note: support for only one check per second
+ */
+bool SCD4x::_isDataReady( void ) {
+
+ unsigned long _curTime = millis();
+ if( (_curTime - _lastCheck) < (unsigned long)(SCD4X_DATA_CHECK_MS) ) return false;
+ _lastCheck = _curTime;
+
+ if( (_curTime -_lastData) >= (unsigned long)(SCD4X_DATA_TIMEOUT)*1000UL ) {
+ // TIMEOUT in data arrival detected !!
+ log_warning(F("\n[SCD4x] data TIMEOUT ?!?! ... restart the chip:s"));log_flush();
+ sw_reset( _i2caddr );
+ return false;
+ }
+
+ uint8_t _retry = 3;
+ bool status = false;
+
+ while( not status and _retry-- ) {
+ // cmd for getting measurement status
+ _writeCmd( _i2caddr, static_cast<uint16_t>(scd4xCmd_t::get_data_ready_status) );
+
+ // read answer (MSB + LSB + CRC)
+ uint8_t buf[3];
+ if( readList_ll(_i2caddr, buf, sizeof(buf)) < sizeof(buf) ) {
+ log_error(F("\n[SCD4x] not enough bytes read !"));log_flush();
+ delay(10); // 1ms is min. delay between commands
+ continue;
+ }
+
+ // check answer's CRC
+ if( not crc_check(buf, 2, buf[2]) ) {
+ log_error(F("\n[SCD4x] CRC check failed !"));log_flush();
+ delay(10); // 1ms is min. delay between commands
+ continue;
+ }
+
+ // then check status
+ uint16_t value = makeWord(buf[0], buf[1]);
+ if( value & (uint16_t)0x07FF ) status = true;
+ break;
+ }
+
+ return status;
+}
+
+
/*
* Check that device identity is what we expect!
*/
@@ -455,38 +491,48 @@ bool SCD4x::_check_identity( uint8_t a ) {
bool status = false;
while( not status and _retry-- ) {
- // cmd for read out status register
+ // cmd for read out serial number
_writeCmd( a, static_cast<uint16_t>(scd4xCmd_t::get_serial_number) );
- // read answer (MSB + LSB + CRC)
+ // read answer 3 * (MSB + LSB + CRC)
uint8_t buf[9];
if( readList_ll(a, buf, sizeof(buf)) < sizeof(buf) ) {
log_error(F("\n[SCD4x] not enough bytes read !"));log_flush();
- delay(1); // min time between commands
- sw_reset( a );
+ delay(10); // 1ms is min. delay between commands
+ sw_reset( a ); delay(10);
continue;
}
// DEBUG
- hex_dump( buf, sizeof(buf) );
+ hex_dump( (char*)buf, sizeof(buf) );
break;
// check answer's CRC
if( not crc_check(buf, 2, buf[2]) ) {
log_error(F("\n[SCD4x] CRC check failed !"));log_flush();
- delay(1); // min time between commands
+ delay(10); // 1ms is min. delay between commands
+ continue;
+ }
+ if( not crc_check(buf+3, 2, buf[5]) ) {
+ log_error(F("\n[SCD4x] CRC check failed !"));log_flush();
+ delay(10); // 1ms is min. delay between commands
+ continue;
+ }
+ if( not crc_check(buf+6, 2, buf[8]) ) {
+ log_error(F("\n[SCD4x] CRC check failed !"));log_flush();
+ delay(10); // 1ms is min. delay between commands
continue;
}
- // TODO: check subsequents word+CRC
-/*
- // finally does status match our expectations
- uint16_t status_reg = buf[0] << 8;
- status_reg |= buf[1];
- if( (status_reg & SHT3X_STATUS_REG_MASK) != SHT3X_STATUS_REG_DEFL ) return false;
+ // DISPLAY retrieved serial number :)
+ {
+ char tmp[48];
+ snprintf(tmp, sizeof(tmp),"\n[SCD4x] serial number = 0x%02X%02X %02X%02X %02X%02X",
+ buf[7],buf[6],buf[4],buf[3],buf[1],buf[0]);
+ log_debug(tmp); log_flush();
+ }
status = true;
-*/
}
// check result
if( not status ) return false;
diff --git a/neosensor/libraries/neocampus_drivers/SCD4x.h b/neosensor/libraries/neocampus_drivers/SCD4x.h
index 8f9d1ba0..44356345 100644
--- a/neosensor/libraries/neocampus_drivers/SCD4x.h
+++ b/neosensor/libraries/neocampus_drivers/SCD4x.h
@@ -33,10 +33,15 @@
/*
* Definitions
*/
-/* SCD4x sensor send back both CO2, T and RH at the same time, but since
- * we'll have three instances of this class ==> we implement a cache to
- * avoid reading the sensor multiple times */
-#define SCD4X_SENSOR_CACHE_MS 5000 // ms caches values validity
+
+/* To avoid checking for the end of the priodic measurement process too often
+ * we set a min delay between two successives check for data readiness */
+#define SCD4X_DATA_CHECK_MS 1000 // ms check data measurement ending
+
+/* In normal operation, periodic measurement leads to new data available very 5s or 30s
+ * (normal vs low-power periodic measurement). If no new data is available for the
+ * specified tiemout, we (soft) reset the end-device */
+#define SCD4X_DATA_TIMEOUT 300 // seconds timeout delay before reseting the chip
// Enable CRC lookup table (regular computation otherwise)
#ifndef SCD4X_CRC_LOOKUP_TABLE
@@ -130,7 +135,8 @@ class SCD4x : public generic_driver {
private:
// -- private methods
- bool _readSensor( uint16_t* ); // low-level function to read value registers
+ bool _readSensor( void ); // low-level function to read sensors values
+ bool _isDataReady( void ); // check is read measurement reached its end
static void sw_reset( uint8_t ); // reset sensor via software reset procedure
static bool crc_check( uint8_t[], uint8_t, uint8_t ); // data array, nb_bytes, checksum
static bool _check_identity( uint8_t ); // check device is what we expect!
@@ -142,14 +148,17 @@ class SCD4x : public generic_driver {
static const char *units_co2;
static const char *units_temp;
static const char *units_rh;
- uint16_t _integrationTime; // ms time to integrate a measure
/* CO2, TEMP and RH are read at the same time ==> hence we store them
as shared attributes across all instances */
- static unsigned long _lastMsRead; // last time data have been read (elapsed ms from beginning)
- static uint16_t _co2_sensor; // shared across all instances
- static uint16_t _t_sensor; // shared across all instances
- static uint16_t _rh_sensor; // shared across all instances
- static boolean _periodic_measure; // if automatic periodic measurement has been activated
+ static boolean _periodic_measure; // automatic periodic measurement already started or not
+ static unsigned long _lastCheck; // last time we check for data readiness (@periodic measurement)
+ static unsigned long _lastData; // last time a new data arrived from SCD4x device
+ static uint16_t _co2_sensor; // shared across all instances
+ static boolean _co2_sensor_valid; // shared across all instances
+ static uint16_t _t_sensor; // shared across all instances
+ static boolean _t_sensor_valid; // shared across all instances
+ static uint16_t _rh_sensor; // shared across all instances
+ static boolean _rh_sensor_valid; // shared across all instances
// CRC computation
static const uint8_t _crc8_polynom; // crc P(x)=x^8+x^5+x^4+1 (0x31) 1.00110001, init=0xFF
diff --git a/neosensor/libraries/neocampus_drivers/SHT2x.h b/neosensor/libraries/neocampus_drivers/SHT2x.h
index ce1a9291..e6effb94 100644
--- a/neosensor/libraries/neocampus_drivers/SHT2x.h
+++ b/neosensor/libraries/neocampus_drivers/SHT2x.h
@@ -34,7 +34,9 @@
*/
// Enable CRC lookup table (regular computation otherwise)
+#ifndef SHT2X_CRC_LOOKUP_TABLE
#define SHT2X_CRC_LOOKUP_TABLE 1
+#endif
/* enable UUID's CRC check
* WARNING: some fakes devices does not support it!
diff --git a/neosensor/libraries/neocampus_drivers/SHT3x.cpp b/neosensor/libraries/neocampus_drivers/SHT3x.cpp
index 7080a1b9..c0a16aea 100644
--- a/neosensor/libraries/neocampus_drivers/SHT3x.cpp
+++ b/neosensor/libraries/neocampus_drivers/SHT3x.cpp
@@ -451,7 +451,7 @@ bool SHT3x::crc_check( uint8_t data[], uint8_t nb_bytes, uint8_t checksum ) {
/*
- * Check that device identity is what we expect!
+ * Write i2c command
*/
void SHT3x::_writeCmd( uint8_t a, uint16_t cmd ) {
write8( a, (uint8_t)(cmd>>8) , (uint8_t)(cmd&0xFF) );
diff --git a/neosensor/libraries/neocampus_drivers/SHT3x.h b/neosensor/libraries/neocampus_drivers/SHT3x.h
index 9d4839b7..89dff250 100644
--- a/neosensor/libraries/neocampus_drivers/SHT3x.h
+++ b/neosensor/libraries/neocampus_drivers/SHT3x.h
@@ -9,6 +9,8 @@
Remember: all transfers are 16bits wide
+ Known issue: only one device per neOSensor (see setup guide)
+
(c) Copyright 2020 Thiebolt.F <thiebolt@irit.fr>
@section HISTORY
diff --git a/neosensor/neosensor.ino b/neosensor/neosensor.ino
index 788e9f86..2af73abc 100644
--- a/neosensor/neosensor.ino
+++ b/neosensor/neosensor.ino
@@ -16,13 +16,18 @@
* - as of aug.20, CONFIG_LWIP_MAX_ACTIVE_TCP=16
*
* ---
+ * KNOWN ISSUES:
+ * - ONLY ONE SHT3x per neOSensor supported.
+ * This stems from the fact that the SHT3x driver features static variables
+ * shared across all instances.
+ *
+ * ---
* TODO:
* - esp8266 now features a configTzTime() in newer API
* - loadSensoConfig --> avoid data duplication, implement an iterator
* - check sntp!=IPADDR_ANY works with ESP8266 (line 400)
* - remove DISABLE_SSL compilation flag
* - as the number of modules is increasing, implement a list of modules in the setup()
- *
* ---
* F.Thiebolt nov.21 corrected timezone definition for esp32
* F.Thiebolt sep.21 added display module support (e.g oled or 7segment displays)
--
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